Tiny, micropower Hall-effect switches deliver compatibility with low-voltage chipsets

Diodes Incorporated introduces three new Hall-effect switches, the AH1899A/B/S, which operate from a low supply voltage and at extremely low quiescent current to extend battery lifetime in mobile and portable devices. The AH1899A/B/S are used to detect the open/closed status of covers and cases for portable electronic devices, such as smartphones and tablets. They are also designed for proximity detection in digital cameras and handheld gaming consoles, as well as general contactless switching.

These switches, with their supply-voltage range of 1.1V to 2.0V, seamlessly integrate with state-of-the-art application chipsets operating at 1.2V, ensuring ease of use. The power-efficient architecture of these parts lowers the typical average operating current to as little as 0.95µA at 1.2V. The hibernating clocking system in these switches help maximise system energy savings to extend the runtime of battery-operated devices.

The omnipolar AH1899A/B/S operate with either north or south magnetic poles close to the package surface. Leveraging an advanced chopper-stabilised topology, the operating (BOP) and release (BRP) points display minimal drift with supply voltage and temperature. Two sensitivity grades are available, giving designers flexibility to tailor the switch response for their application. The AH1899B and AH1899S operate when the magnetic field strength (B) exceeds 30 Gauss and release at below 20 Gauss. The AH1899A is a high-sensitivity version that operates at 18 Gauss and releases at 12 Gauss. All versions remain off when no field strength is present.

Designers can also take advantage of board-space savings by selecting these switches, which are packaged as X2-DFN1010-4 (Type B) surface-mount devices. At just 1.0mm x 1.0mm, and 0.4mm high, the footprint is smaller than typical alternatives. In addition, the internal circuitry integrates pull-up and pull-down resistors to save the PCB area usually needed for external components.